Hereditary, the startling and assured feature debut by writer/director Ari Aster anchored by a stunning performance by Toni Collette, may be the creepiest movie in several decades.

And that’s saying something, given that in the last few years we’ve seen some spectacular brainy-over-gory horror movie home runs. Among them: this year’s A Quiet Place, and, other recent, beautifully made disturbing movies like It Follows, The Witch and The Babadook.

In style and subject, the film harkens back to horror movies of the late ‘60s/early ‘70’s like Rosemary’s Baby and The Mephisto Waltz, character driven movies that pitted very modern and sophisticated lead characters against the darker ends of the occult, intoning ritual incantations from the dusty past.

Hereditary opens with a death notice. The dearly departed is Ellen Graham, mother of Annie (Toni Collette), mother-in law to Steve (Gabriel Byrne), and grandmother to stoner teenager Peter (Alex Wolff) and his younger sister Charlie (Milly Shapiro), the latter of whom seems to have some unspecified developmental issues.

And now there’s a funeral to attend.

Annie talks about the strained relationship with her mother in her eulogy, hinting at deep mental illnesses that may run in the family. But that’s just the beginning of their problems.

The family lives in a big, beautiful, albeit dark, house with lots of places to gather. But everyone retreats to their own space when they get home. It’s as disquieting in this house, as it is quiet.

After her mother’s death Annie seems to have trouble coping. She’s jumpy and unpredictable. And soon there are more things, shocking things, to challenge what seems like her already tenuous grip on sanity.

Heredity is a long movie, just over two hours. But Aster doesn’t rush or fill the time with unnecessary noise or action. Instead he takes the long, slow approach, focusing the camera on the faces of the characters as they react and absorb. There’s a creeping claustrophobia – to the point that it’s a toss up whether the tension will kill you or the characters.

Adding to that atmosphere, Aster plays with things that have creeped all of us out in our own homes. The familiar chair in the corner of the bedroom that seems to take on a terrifying shape in the middle of the night, etc.

The performances are strong, particularly by Wolff, the teenage son coping with life through a druggy haze. But the movie belongs to Collette, in whose capable hands the character’s extreme mood swings seem plausible. A lesser actor in that role would have toppled the whole movie into deep fromage.

Aster says that he first conceived Hereditary as a family drama, and then as a genre film, and he gives us both in equal measure. Almost everyone is dealing with some sort of inner demon, even before we get to the point of wondering whether there are real demons at work.

The movie works on many levels: a metaphor of a family spiral into dysfunction; a family dealing with grief and even a teenager’s paranoid distrust for authority. And like the best horror movies, this one, with its themes of free will versus destiny, speak to the times in which we live.

Horror movies that deal with the occult work best when they adhere to known, actual rites and rituals of occult liturgy, otherwise they veer off into the ridiculous. Aster appears to have done his research. Although in a very contained focused film, that occultish climax is where he lets loose - arguably overplaying it a bit in an otherwise measured movie.

Whether that will put you off or just add to the thrill is in the psyche of the beholder. For sure, this is not for the faint of heart. Hereditary, with some pretty potent imagery, fulfills its creepiest goals.